Repointing

[Andygasman2010]

Hi guys, just after some advice on repointing my house due to some penetrating damp.

I have a back to back terrace house, I think over 100 yrs old, and upstairs inside has damp on the walls coming through. I can see marks on the outside and the mortar is in poor condition so i'm pretty sure repointing is the answer. I was going to give this a go myself but afetr reading about it I think it might be a bit much to take on.

I was thinking ladders, angle grinder and sand/cement but from what I've read this could be a disaster! Anyone have any advice?

Or if there are any builders in the Leeds area fancy giving me a quote let me know.

Thanks, Andy.

 

[stuart45]

Andy,
If you have soft brickwork with lime mortar joints re-pointing with a hard cement mortar could cause damage to the brickwork in time. If the joints are really soft I usually cut them out with a plugging chisel.
You only have to look at some jobs to see what a mess of the wall re-pointing can do.
I'm not saying that all re-pointing specialists do a bad job, but I do know a few who only got into re-pointing because they couldn't hack it on the trowel.

 

[Andygasman2010]

What's the best mix of mortar to use?

Or does it depend on what kind of bricks you have?

Thanks.

 

[stuart45]

It does depend on the type of brick, climate, exposure etc. As a general rule, if the mortar has lasted 50 years or more you would be looking to re-point with a similar mix. Mortar joints are designed to be sacrificed in time to preserve the brickwork.
A 2 or 3 to 1 sand/NHL3.5 lime should be OK, or you get it ready mixed.

 

[^woody^]

One thing to remember is that the weather resistance of the joint relies on the mortar being properly ironed (ie smoothed and compacted) to close the pores and shed water

You probably want to practice at ground level before venturing up a ladder with a grinder and coming back down with no eye or a sliced arm

Also, use a proper thick mortar raking disk, not one of the thinner cutting disks